In a desperate attempt to escape another "lesson" (bullying session) from Jake "the Snake,"
Mouse
and his friends Shelby and Lucy take shelter in the old, supposedly haunted, Holsom barn. When
one
of Jake's friends, Jorge, discovers them hiding in the barn's silo, a scuffle breaks out and a
hidden button is accidentally pressed. Suddenly the silo floor descends like an elevator!

Once the elevator stops, our gang makes their first discovery: Horatio Holsom, the eccentric
old
inventor who disappeared over forty years before, built an enormous underground laboratory
below his
family's farm. The place is packed with incredible gadgets, but only Mouse—a near genius with
computers—is interested in staying. The elevator seems broken, and Jorge is still intent on
roughing
up Mouse. Their arguments are interrupted by a cold, metallic voice. The four kids learn they
are
not alone in the compound.